CyberSecBulletin
CVE-2022-20738NVD status: Modified

Cisco Umbrella Insights Virtual Appliance: Protection Mechanism Failure

CVE-2022-20738 is a critical-severity protection mechanism failure vulnerability in Cisco Umbrella Insights Virtual Appliance from Cisco, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 1.1% chance of exploitation within 30 days, higher than 66% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of Cisco Umbrella Insights Virtual Appliance you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on tools.cisco.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
CiscoCisco Umbrella Insights Virtual ApplianceNot specified in the recordNot stated
CiscoUmbrella Secure Web GatewayNot specified in the recordNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.15.8MediumCNA (cisco.com)
CVSS 3.19.8CriticalNVD
CVSS 2.07.5HighNVD

Official description

A vulnerability in the Cisco Umbrella Secure Web Gateway service could allow an unauthenticated, remote attacker to bypass the file inspection feature. This vulnerability is due to insufficient restrictions in the file inspection feature. An attacker could exploit this vulnerability by downloading a crafted payload through specific methods. A successful exploit could allow the attacker to bypass file inspection protections and download a malicious payload.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Protection Mechanism Failure

The product does not use or incorrectly uses a protection mechanism that provides sufficient defense against directed attacks against the product.

More Protection Mechanism Failure vulnerabilities (CWE-693)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Cisco Umbrella Insights Virtual Appliance

All Cisco Umbrella Insights Virtual Appliance vulnerabilities

Recent Protection Mechanism Failure vulnerabilities

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